- Posts: 1
- Joined: Tue Dec 11, 2012 3:20 pm
Tue Dec 11, 2012 3:23 pm
Hi,
I'm trying to develop an application that gets CEA-708 from HD-SDI (1080i 59.94) using a Blackmagic DeckLink card (HD Extreme 3D). I already got anc packets (identified by header 0x000 0x3FF 0x3FF), got CDP (caption distribution packet) and everything else. My problem is that CDP counter is ok (counts by 1 every new frame), but sequence counter inside DTVCC Channel Packet (2 bits) doesn't increment correctly. As consequence, I get corrupted caption (missing chars). By the other hand, a Tektronix Analyser can correctly decode the CEA-708 in this HD-SDI signal. Am I missing something? Does Blackmagic modify these DTVCC packets?
It's worth mentioning that the same behavior occured with two different sources of HD-SDI signal.
Thanks.
Best regards,
André Reis.
I'm trying to develop an application that gets CEA-708 from HD-SDI (1080i 59.94) using a Blackmagic DeckLink card (HD Extreme 3D). I already got anc packets (identified by header 0x000 0x3FF 0x3FF), got CDP (caption distribution packet) and everything else. My problem is that CDP counter is ok (counts by 1 every new frame), but sequence counter inside DTVCC Channel Packet (2 bits) doesn't increment correctly. As consequence, I get corrupted caption (missing chars). By the other hand, a Tektronix Analyser can correctly decode the CEA-708 in this HD-SDI signal. Am I missing something? Does Blackmagic modify these DTVCC packets?
It's worth mentioning that the same behavior occured with two different sources of HD-SDI signal.
Thanks.
Best regards,
André Reis.
